Two-leg walking humanoid robot

ABSTRACT

It is a biped (two-footed) walking humanoid robot, which is provided with drive motors ( 11   d,    11   e   , 18 L,  18 R- 24 L,  24 R,  28 L,  28 R- 33 L,  33 R,  35, 36 ) to pivotally move respective joint portions, and a motion control apparatus ( 40 ) to drive-control respective drive motors, and said motion control apparatus ( 40 ), together with a detector ( 45 ) to detect the robot&#39;s current posture and others, compares the robot&#39;s detected current posture and others with next motion command input from outside, and if next motion command is within the range of stability limit with respect to the robot&#39;s current posture and others, the complementary data with respect to intermediate motion from current posture till initial posture of next motion command and the motion data corresponding to next motion command are generated, each drive motor is drive-controlled based on said complementary and motion data, and thereby various motions are conducted smoothly and continually. It is preferably provided with a motion library ( 41   a ) storing time series data of basic motions as the elements of the robot&#39;s motions and posture data consisting of algorithm, reads out the corresponding posture data from said motion library, and generates complementary and motion data as the combined motion sequence.

TECHNICAL FIELD

The present invention relates to a biped (two-footed) walking humanoidrobot, and more specifically to a biped (two-footed) walking humanoidrobot capable of conducting various motions smoothly and continually.

BACKGROUND ART

A conventional biped walking humanoid robot generates the pre-designedwalk pattern (hereinafter to be called “gait”) data, conducts walkcontrol according to the gait data, moves leg portions by thepre-designed walk pattern, and thereby realizes biped walking. Here, inorder to stabilize walk posture, stabilization of the robot is targetedby ZMP regulation by what is called ZMP Compensation, whereby a point onthe sole of a foot of the robot where the composite momentum of floorreaction force and gravity becomes zero is converged to the targetvalue.

Incidentally as a biped walking humanoid robot's motions, in addition towalking, uprising motion without walking, so-called rotational motionsto change direction, or stand up motion from sitting posture on a chair,and others can be mentioned. In order to realize a more practicalhumanoid robot, such various motions have to be conducted quickly andsmoothly.

However, such motions are designed to be conducted independently of oneanother, and, in case respective motions are conducted in series, theyare not continuous and smooth in general. Especially, continuation ofquick motions tends to cause the robot's tumbling down due tounbalancing caused by inertial force generated from respective motions.For this reason, conventional biped walking humanoid robots arecontrolled, after one motion is completed, to stop once, and slowly moveto another motion, thereby their motions look quite mechanical.

Further conventional biped walking humanoid robot are in many casesoperated by an operator with outside control system for convenience andreal time motions, for which menu display, operation buttons, orjoysticks are provided to the control system for choosing motion, andthe motion for the robot to conduct is chosen by using said parts.Therefore, when the operator chooses next motion for the robot toconduct and the robot conducts the chosen next motion, the robot maytumble down by unbalancing, or the drive means to drive its each partmay be overloaded by unnatural posture. Thus, it has so far beendifficult for a biped walking humanoid robot to conduct various motionscontinually and smoothly.

DISCLOSURE OF THE INVENTION

It is the objective of the present invention, taking into considerationthe above-mentioned problems, to provide a biped walking humanoid robotcapable of easily conducting various motions continually and smoothly.

The above-mentioned objective is achieved in accordance with the presentinvention with the biped walking humanoid robot, which comprises a bodyportion, a pair of leg portions attached at both sides of the lower partof said body portion each pivotally movable, each of the leg portionshaving a knee portion in its midway and a foot portion at its lower end,a pair of arm portions attached at both sides of the upper part of saidbody portion each pivotally movable, each of the arm portions having anelbow portion in its midway and a hand portion at its lower end, and ahead portion attached on top of said body portion, the drive means topivotally move the pivotally movable joint portions of the foot, lowerthigh, and thigh portions of said leg portions, and the hand, lower arm,and upper arm portions of said arm portions, and the motion controlapparatus to drive-control each drive means, characterized in that saidmotion control apparatus, together with a detector to detect the robot'scurrent posture and others, compares the robot's current posture andothers detected by said detector with next motion command input fromoutside, and if next motion command is within the range of stabilitylimit with respect to the robot's current posture and others, thenmotion data is generated corresponding to next motion command, and eachdrive means is drive-controlled based on said motion data.

In accordance with the above-described aspect, for a biped walkinghumanoid robot to conduct various motions continually, only when nextmotion command is within the range of stability limit, motion datacorresponding to next motion command is generated. Therefore, by saidmotion control apparatus drive-controlling the robot's each portionbased on said motion data, the robot can conduct the motion by nextmotion command from the current posture, and continuous motion can beconducted smoothly and stably.

Also since, only when next motion command is within the range ofstability limit, the robot conducts the motion corresponding to nextmotion command, even if an operator to operate the robot isunaccustomed, the suitability and unsuitability of each continued motionare not required to be judged by the operator by combination of variousmotions by the robot operation, therefore easy operation of complexcontinuous motion is possible, and thereby conduction of unsuitablemotion by wrong operation by the operator can be prevented.

A biped walking humanoid robot in accordance with the present inventionis preferably such that said motion control apparatus compares therobot's current posture and others detected by the detector and nextmotion command input from outside, and if next motion command is withinthe range of stability limit with respect to the robot's current postureand others, then complementary data with respect to the intermediatemotions from the robot's current posture till the initial posture ofsaid next motion command and motion data corresponding to next motioncommand are generated, and each drive means is drive-controlled based onsaid complementary and motion data.

Thus, a robot, with its motion control apparatus drive-controlling itseach part based on said complementary and motion data, conducts themotion by next motion command from the current posture via theintermediate motion. Therefore, since a robot conducts the motion bynext motion command from the terminal position of the previous motionvia the intermediate motion by complementary motion, continuous motioncan be conducted smoothly and stably.

A biped walking humanoid robot in accordance with the present inventionis preferably such that said motion control apparatus is provided with amotion library storing any combination of time-series data of basicmotions, and posture data generating algorithm, as the elements of therobot's motions, and, upon generating complementary and motion data withrespect to the intermediate motion from the robot's current posture tillthe initial posture of next motion command, reads out the correspondingposture data from the motion library, and generates complementary andmotion data as the combined motion sequence.

According to the above-described aspect, since the posture data of basicmotions is stored in motion library as the decomposed elements of therobot's various motions, the motion control apparatus can, upongenerating complementary and motion data, generate desired complementaryand motion data by reading out on real time and combining posture datafrom motion library as the elements of basic motions. Thus, sincevarious motions are realized by real time combination of basic motions,in case that a robot is actually operated under the same circumstance ashuman beings, that is, the circumstance where the predicted conditionsand reality do not necessarily agree because the circumstance variesirrelevantly with the robot operation, and also it varies due to therobot's own action, the robot can react flexibly to the condition of thecase. Further, the volume of calculation by the motion control apparatusis reduced, thereby quick generation of complementary and motion data ispossible.

A biped walking humanoid robot in accordance with the present inventionis preferably such that said motion control apparatus is provided withmemory means to memorize the motion commands from outside, and, withrespect to the frequently designated specific continuous motion command,stores its posture data as new basic data into motion library. In thiscase, when a group of the frequently designated specific continuousmotion command is input from outside, the posture data corresponding tosaid group of motion command stored in motion library can be read out,and can be made motion data as it is. Therefore, the calculation of thecombined sequence of basic motions becomes unnecessary, and the motiondata corresponding to a group of said motion command can be generatedeasily and quickly.

A biped walking humanoid robot in accordance with the present inventionis preferably such that said motion control apparatus does not generatemotion data based on next motion command, and does not conduct saidmotion, if next motion command is outside of the range of stabilitylimit with respect to the robot's current posture and others. Thus, bynot conducting the motion with respect to motion command outside of therange of stability limit for the robot's current posture and others, itcan be prevented in advance for a robot to be unstable and tumble downby the motion corresponding to next motion command.

A biped walking humanoid robot in accordance with the present inventionis preferably such that said motion control apparatus, if next motioncommand is outside of the range of stability limit with respect to therobot's current posture and others, indicates another motion to outsidewithin the range of stability limit with respect to the robot's currentposture and others. Therefore, in case that next motion command inputfrom outside is outside of the range of stability limit with respect tothe robot's current posture and others so that said motion is notconducted, by indicating another motion possible, for example, to therobot operator, said operator can choose appropriate motion out of theindicated motions for substitution, and input new next motion command tothe robot.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will better be understood from the followingdetailed description and the drawings attached hereto showing certainillustrative forms of embodiment of the present invention. In thisconnection, it should be noted that such forms of embodiment illustratedin the accompanying drawings hereof are intended in no way to limit thepresent invention but to facilitate an explanation and an understandingthereof, in which drawings:

FIG. 1 illustrates an outlook of a biped walking humanoid robotaccording to the present invention as one form of embodiment thereof, inwhich (A) is a schematic front view, and (B) is a schematic side view;

FIG. 2 is a block diagram illustrating the mechanical makeup of a bipedwalking humanoid robot shown in FIG. 1;

FIG. 3 is a schematic view illustrating the forward pivotal limit of theforward bending portion and each joint portion of leg portions of abiped walking humanoid robot shown in FIG. 1;

FIG. 4 is a schematic view illustrating the backward pivotal limit ofthe forward bending portion and each joint portion of leg portions of abiped walking humanoid robot shown in FIG. 1;

FIG. 5 is a schematic view illustrating each joint portion of theforward bending portion of a biped walking humanoid robot shown in FIG.1, in which (A) shows the leftward rotational limit, and (B) shows therightward rotational limit, respectively;

FIG. 6 is a block diagram illustrating the electrical makeup of a bipedwalking humanoid robot shown in FIG. 1;

FIG. 7 is a flowchart illustrating the motion control of a biped walkinghumanoid robot shown in FIG. 1;

FIG. 8 is a view illustrating an example of the motion of a bipedwalking humanoid robot shown in FIG. 1;

FIG. 9 is a view illustrating in order the robot's posture andindication during the motion of FIG. 8.

BEST MODES FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail withreference to suitable forms of embodiment thereof illustrated in thefigures.

FIG. 1 and FIG. 2 show the makeup of an embodiment of a biped walkinghumanoid robot in accordance with the present invention. Referring toFIG. 1, a biped walking humanoid robot 10 includes a body portion 11, apair of leg portions 12L and 12R attached to both sides of the lowerpart of the body portion 11, a pair of arm portions 13L and 13R attachedto both sides of the upper part of the body portion, and a head portion14 attached to the top of the body portion.

The body portion 11 is divided to a breast portion 11 a as an upper partand a waist portion 11 b as a lower part, and the breast portion 11 a issupported at a forward bending portion 11 c pivotally movably in theforth and back direction with respect to the waist portion 11 b, andespecially forward direction, and rotationally left and right. Further,in the breast portion 11 a of the body portion 11, a walk controlapparatus 50 is contained as described below. The forward bendingportion 11 c is provided with a joint portion 11 d for forth and backpivotal movement and a joint portion 11 e for rotation left and right,and each joint portion 11 d and 11 e comprises a joint drive motor (SeeFIG. 2.), respectively.

The leg portions 12L, 12R are made up with thigh portions 15L, 15R,lower thigh portions 16L, 16R, and foot portions 17L, 17R. The legportions 12L, 12R are provided, as shown in FIG. 2, with six jointportions, respectively, in the order from upper side, joint portions18L, 18R for the rotation of the leg portions with respect to the waistportions 11 b of the body portion 11, joint portions 19L, 19R in theroll direction (around x axis) of the leg portions, joint portions 20L,20R in the pitch direction (around y axis) of the leg portions, jointportions 22L, 22R in the pitch direction of knee portions 21L, 21Rconnecting thigh portions 15L, 15R and lower thigh portions 16L, 16R,joint portions 23L, 23R in the pitch direction of ankle portions withrespect to the foot portions 17L, 17R, and joint portions 24L, 24R inthe roll direction of the ankle portions. Here, each joint portion 18L,18R to 24L, 24R comprises a joint drive motor, respectively.

Thus, a waist joint is made up with the joint portions 11 d, 11 e, and ahip joint is made up with the joint portions 18L, 18R, 19L, 19R, 20L,and 20R, and foot joints are made up with the joint portions 23L, 23R,24L, and 24R. Accordingly, the leg portions 12L, 12R on both sides, leftand right, of the biped walking humanoid robot 10 have six degrees offreedom, respectively, and it is made capable of walking at will in athree dimensional space by drive-controlling these twelve joint portionsduring various motions with respective drive motors at appropriateangles, and by giving desired motions to whole leg portions 12L, 12R.

The arm portions 13L, 13R are made up with upper arm portions 25L, 25R,lower arm portions 26L, 26R, and hand portions 27L, 27R, respectively.The upper arm portions 25L, 25R of the arm portions 13L, 13R, the lowerarm portions 26L, 26R, and the hand portions 27L, 27R are provided, asshown in FIG. 2 like above-mentioned the leg portions 12L, 12R, withfive joint portions, respectively, in the order from upper side, jointportions 28L, 28R for the pitch direction of the upper arm portions 25L,25R at shoulder parts with respect to the body portion 11, jointportions 29L, 29R in the roll direction of the upper arm portions 25L,25R at shoulder parts, joint portions 30L, 30R in the left and rightdirection of the upper arm portions 25L, 25R at shoulder parts, jointportions 32L, 32R in the pitch direction of elbow portions 31L, 31Rconnecting the upper arm portions 25L, 25R and the lower arm portions26L, 26R, and joint portions 33L, 33R in the pitch direction of the handportions 27L, 27R at a wrist part with respect to the lower arm portions26L, 26R. Here, each joint portion 28L, 28R to 33L, 33R comprises ajoint drive motor, respectively.

Thus, the arm portions 13L, 13R on both sides, left and right, of thebiped walking humanoid robot 10 have five degrees of freedom,respectively, and it is made capable of drive-controlling these twelvejoint portions during various motions with respective drive motors atappropriate angles, and giving desired motions to whole arm portions13L, 13R. Here, the rotation axis of the joint portions 28L, 28R in thepitch direction at said shoulder parts is set misaligned forward withrespect to the joint portions 29L, 29R in the roll direction and thejoint portions 30L, 30R in the left and right direction, and the swingangle forward of the arm portions 13L, 13R is designed larger.

The head portion 14 is attached on to the top end of the upper portion11 a of the body portion 11, and is provided, for example, with a cameraas visual perception and a microphone as auditory perception. The headportion 14 comprises, as shown in FIG. 2, a joint portion 35 in thepitch direction of a neck and a joint portion 36 in the left and rightdirection. Here, each joint portion 35, 36 are made up with respectivejoint drive motor.

Thus, the head portion 14 of the biped walking humanoid robot 10 has twodegrees of freedom, and it is made capable of moving in the left andright and forth and back directions by drive-controlling these two jointportions 35, 36 during various motions with respective drive motors atappropriate angles. Here, the rotation axis of the joint portion 35 inthe pitch direction is set misaligned forward with respect to the jointportion 36 in the left and right direction, and the pivotal angleforward of the head portion 14 is designed larger.

Further in the biped walking humanoid robot 10, the joint portion 11 dof the forward bending portion 11 c of the body portion 11, jointportions in the forth and back direction of the leg portions 12L, 12R,that is, the joint portions 20L, 20R of the hip joint, the jointportions 22L, 22R of the knee portions, and the joint portions 23L, 23Rof the ankle portions are supported pivotally movably in the angle rangeshown in FIG. 3 and FIG. 4. The joint portions 23L, 23R of the ankleportions are capable of pivotally moving in the angle range where itspivotal angle θ1 is −20 to +20 degrees or more. The joint portions 22L,22R of the knee portions are capable of pivotally moving in the anglerange where its pivotal angle θ2 is −120 to 0 degrees or more. The jointportions 20L, 20R of the waist portions are capable of pivotally movingin the angle range where its pivotal angle θ3 is −45 to +60 degrees ormore. The forward bending portion 11 c of the body portion 11 is alsocapable of pivotally moving in the angle range where its pivotal angleθ4 is −10 to +60 degrees or more. On the other hand, the joint portion11 e of the forward bending portion 11 c of the body portion 11 issupported pivotally movably in the angle range as shown in FIG. 5. Thatis, the joint portion 11 e of the forward bending portion 11 c of thebody portion 11 is capable of pivotally moving in the angle range whereits pivotal angle θ5 is −45 degrees or more in the left-side directionshown in FIG. 5(A), and +45 degrees or more in the right-side directionshown in FIG. 5(B).

FIG. 6 shows the electrical makeup of the biped walking humanoid robot10 shown in FIG. 1 to FIG. 5. In FIG. 6, the biped walking humanoidrobot 10 is provided with a drive means, that is, a motion controlapparatus 40 to drive-control the above-mentioned respective jointportions, that is, the joint drive motors 11 d, 11 e, 18L, 18R to 36.

The motion control apparatus 40 is provided with a motion planner 41, amotion generator 42, a compensator 43, a controller 44, an anglemeasurement unit 45 as a detector to detect angles of respective jointportions of the robot, a ZMP detection sensor (not shown in the figure)provided to the foot portions 17L, 17R, and a motion monitor 46. Here,as a coordinate system of the biped walking robot 10, xyz coordinatesystem is used in which the forth and back direction is defined as xdirection (forth as +), the horizontal direction as y direction (inwardas+) and the vertical direction as z direction (upward as +).

The motion planner 41 plans the motions corresponding to the motioncommands based on next motion command input from outside. That is, themotion planner 41 calculates the angular momentum of each portion of therobot required for the motion corresponding to said motion command, andmakes up a robot's motion path, that is, the motion plan. Here, in themotion planner 41, a robot's current posture and others are input fromthe motion monitor 46 as described below, and the robot's currentposture and others are referred to upon making up of the motion plan. Asthe motion command input from outside, arbitrary motion command can bechosen by the operator, for example, using a joystick, a mouse, or anoperation button in the external control system 47. The motion planner41 preferably displays, as described below, the motion to be currentlychosen by the screen display or others on the external control system47, referring to the robot's current posture and others.

Here, the motion planner 41 is provided with a motion library 41 a. Themotion library 41 a stores in advance the posture data and others ofbasic motions as the elements of a robot's motion as the databaseaccording to classifications. The posture data is the program togenerate the time-series data and motion of a robot's joint parameters.And the posture data includes the auxiliary description about motion,for example, the time to be spent, a robot's part on which the motion isapplied, and the basic object of use of the motion, and others, andaccordingly, a robot can judge the additional information which isessentially understood by humans. The posture data also includes thesurrounding conditions (for example, the hindrance in front during walkforward, and the like) required to conduct motions, and the stabilityindices (for example, ZMP and the position of center of gravity, and thelike) upon start and finish of a robot's motions. The posture datafurther includes main parameter and its variable range and other, if themotion is not fixed motion but the output is variable by adjusting theparameter. Here, the auxiliary description means, for example, standupmotion, rotational motion, and stepping motion, and others as possiblemotions in currently sitting down state.

Accordingly, the motion planner 41 chooses and reads out variousnecessary posture data and others from the motion library 41 a upon theabove-mentioned motion planning, generates motion plan as the sequenceof combined motions, and outputs posture data of each sequence as motionplan to the motion generator 42. In this case, a robot's current postureand others are input from the motion monitor 46, and the motion planner41 compares the robot's current posture and next motion command uponconducting motion plan, and judges if it is possible to conduct themotion by next motion command within the stability range from therobot's current posture and others. In this case, the motion planner 41can easily judge by referring to the auxiliary description of respectivemotion data stored in the motion library 41 a. And if the motion by nextmotion command is out of stability range, then the motion planner 41does not conduct the motion plan based on the next motion command, butdenotes the motion to be chosen by the robot's current posture andothers to the outside control system, for example, on screen display orothers. If, on the other hand, the motion by next motion command iswithin stability range, then the motion planner 41 judges whethertransfer is possible to the motion by next motion command from therobot's current posture. In this case, too, the motion planner 41 caneasily judge likewise by referring to the auxiliary description ofrespective motion data stored in the motion library 41 a.

In case that the motion can be stably transferred by next motioncommand, the motion planner 41 reads out the corresponding posture datafrom the motion library 41 a based on next motion command, and generatesmotion plan. On the other hand, in case that the motion can not bestably transferred by next motion command, the motion planner 41conducts complementary calculation with respect to the intermediatemotion from the robot's current posture till the initial state of themotion by next motion command, or reads out the posture datacorresponding to the intermediate motion from the motion library 41 a,and generates motion plan for complementary motion, as well as reads outthe corresponding posture data from the motion library 41 a based on themotion by next motion command and generates motion plan, and outputs themotion plan for both complementary motion and the motion by next motioncommand to the motion generator 42. Here, the posture data about theabove-mentioned complementary motion includes auxiliary description asto whether usable for, for example, the transfer from certain posture toanother posture. Further, the motion planner 41 records the motioncommand from outside into a history filter 41 b as a memory device.Accordingly, the history filter 41 b, upon inputting a group of motioncommands about a plurality of frequently continuing motions, registersthe motion by such group of motion commands into the motion library 41 aas a new basic motion.

The motion generator 42 generates angle data, as motion data, ofrespective joint portions 15L, 15R to 36 required for the motion of thebiped walking humanoid robot 10. In this case, the motion generator 42modifies internal parameters and angle data base on the command, asdescribed later, from the compensator 43.

The compensator 43 calculates ZMP (Zero Moment Point) target value basedon the angle dataθref of respective joint portions from the motiongenerator 42, as well as ZMP real value based on the posture informationfrom an angle measurement unit 45 and the detected output from the ZMPdetection sensor. And the compensator 43 compares the ZMP real valuewith ZMP target value, calculates ZMP compensation based on theirdifference, and outputs it to the motion generator 42. Here, the motiongenerator 42, with ZMP compensation fed back from the compensator 43,modifies motion data based on said ZMP compensation, and outputs it tothe controller 44. The controller 44 generates the control signals forrespective joint drive motors based on the modified motion data from themotion generator 42, and drive-controls respective joint drive motors.

The angle measurement unit 45, with the angle information of respectivejoint drive motors input by, for example, a rotary encoder or the likeprovided to joint drive motors of respective joint portions 11 d, 11 e,18L, 18R to 36, measures the angle positions of respective joint drivemotors, that is, the state information about angle, angle velocity, androtation moment, that is, the posture information θ real of the robot10, and outputs it to the compensator 43 and the motion monitor 46.

The motion monitor 46, with motion plan from the motion planner 41, ZMPtarget value from the compensator 43, and the angle information as ZMPreal value (including angle and angle moment) from angle measurementunit 45 and ZMP detection sensor input thereinto, always monitors thestate of the biped walking humanoid robot 10 based on these data. Andthe motion monitor 46 feeds back motion plan, the deviation of a robot'sreal motion from ZMP target value, and a robot's current posture andothers to the motion planner 41. Further, the motion monitor 46, when arobot's state becomes unstable, commands compensation or termination ofmotion for stabilization to the motion planner 41.

The biped walking humanoid robot 10 in accordance with embodiments ofthe present invention is made up as described above, and moves as shownin the flowchart of FIG. 7. First of all at step ST1, the motion planner41 takes up a robot's current posture and others from the motion monitor46, takes up practicable motion corresponding to a robot's currentposture and others from the motion library 41 a at step ST2, and denotesthese motions to the controller 47. And the motion planner 41 takes upat step ST3 the motion command about next motion input from a controller47 by an operator, and the motion planner 41 judges at step ST4 if saidnext motion command is practicable within the stability range incomparison with a robot's current posture and others.

Here, in case within the range of stability limit, the motion planner 41registers at step ST5 said next motion command to the history filter 41b, and at step ST6, judges whether said next motion command is themotion frequently applied. If the next motion command is the motionfrequently applied, the motion planner 41 registers additionally at stepST7 said next motion command which was registered to the history filter41 b to the motion library 41 a as a new basic motion. After that, themotion planner 41 proceeds on to step ST8. On the other hand, if thenext motion command is not the motion frequently applied, the motionplanner 41 proceeds on to step ST8. The motion planner 41 judges at stepST8 if the robot can stably transfer to the motion by next motioncommand from a robot's current posture. And if not stably transferable,the motion planner 41 applies complementary motion at step ST9, andafter generating complementary motion plan as intermediate motion from arobot's current posture till the initial posture by next motion command,or if stably transferable, then proceeds on to step ST10 and generatesmotion plan of the motion by next motion command.

Thus, after the motion planner 41 generates motion plan andcomplementary motion plan, the motion generator 42 generates motion dataand complementary motion data based on said motion plan andcomplementary motion plan, and the controller 43 drive-controls thejoint drive motors of a robot's respective joint portions according tosaid motion data and complementary motion data. And, while the robotconducts the above-mentioned motions, the motion monitor 46 predicts therobot's state based on the robot's posture and the observed ZMP value atstep ST10, and judges at step ST11 if acting stably. If acting stably,the robot continues the motion, and the motion monitor 46 judges whetherto finish motion or not at step ST12. And said step ST10 to ST12 arerepeated till the motion is finished. If motion is finished, the motionmonitor 46 controls at step ST13 the motion planner 41, the motiongenerator 42, and the controller 43, and finishes motion. On the otherhand, if not acting stably at step ST11, the motion monitor 46 proceedson to step ST13, instantly outputs motion termination command to themotion planner 41, and the motion planner 41 stops motion plan, and therobot's motion is finished.

Further at said step ST4, if the motion by next motion command is notpracticable motion, the motion planner 41 retrieves the posture datacorresponding to the intermediate motion from a robot's current posturetill the initial posture of the motion by next motion command from themotion library 41 a. And at step ST15, if there is not such posture datacorresponding to the intermediate motion, the motion planner 41 proceedson to step ST13, instantly stops motion plan, and the robot's motion isfinished. On the other hand, if there is such posture data correspondingto the intermediate motion, the motion planner 41 denotes suchintermediate motion by screen display or others on the controller 47 atstep ST16, and returns to step ST3.

Thus, as for the biped walking humanoid robot 10 in accordance withembodiments of the present invention, when a motion is conducted by nextmotion command referring to the robot's current posture and others, suchmotion impossible to be continuous is not conducted, thereby the robot'svarious motions are made possible without damaging the robot'sstability. Accordingly, a biped walking humanoid robot's continuous,smooth, stable, and firm motion is made possible.

Next, as shown, for example, in FIG. 8, explanation will be made for thesitting state of the biped walking humanoid robot 10.

The motion planner 41 preferentially denotes the motion previouslychosen by an operator on a screen display or others of the controller47, based on the robot's current posture “sitting position” as shown inFIG. 9(A), as next motion from complementary explanation registeredabout the robot's sitting position A (See FIG. 8.) from the motionlibrary 41 a, then followed by “stand up motion, rotational motion,stepping motion” originally registered in the motion library 41 a. Here,among the list of denoted motions, the motions impossible to conduct areincluded, and are possible to be chosen forcibly by an operator.

Here, as shown in FIG. 9(B), if rotational motion (indicated with symbolB in FIG. 8) is chosen from the controller 47 by an operator as nextmotion, the motion planner 41 retrieves the posture data aboutrotational motion in the motion library 41 a based on next motion fromthe controller 47.

And since standing position C is the prerequisite for rotational motionB from complementary explanation of said posture data, the motionplanner 41 does not accept this next motion command, and since, forexample, stand up motion is required as complementary motion withrespect to rotational motion B from sitting position A, the motionplanner 41 outputs, as shown in FIG. 9(C), said stand up motion to thecontroller 47 as complementary motion, and denotes it to its screendisplay and others.

Here, if an operator chooses stand up motion as said complementarymotion by the controller 47, the motion planner 41 records into thehistory filter 41 b stand up motion and rotational motion as a series ofbasic motions about rotational motion from sitting position, andconducts in series stand up motion as shown in FIG. 9(D), and rotationalmotion as shown in FIG. 9(E).

Here, in case that there are a plurality of complementary motions from arobot's current posture till the motion by next motion command, allcomplementary motions are denoted on a controller 47 by screen displayor others, and an operator can choose any of the complementary motions.In case of a plurality of complementary motions, if no time is left tochoose complementary motion to conduct a robot's motion in real time, acomplementary motion may be preferably automatically chosen after acertain time in the preferential order pre-determined in advance byoff-line.

Here, in case that there is no complementary motion for the initialposture of next motion command, or in case that a robot's stability cannot be guaranteed by complementary motion, the motion planner 41 cancelsnext motion command, and stops conduction of motion.

According to the above-mentioned embodiment, leg portions 12L, 12R havesix degrees of freedom, and arm portions 13L, 13R have five degrees offreedom, but not limited as such, they may have less or more degrees offreedom.

Also according to the above-mentioned embodiment, the controller 47 isoperated by an operator, but not limited as such, input operation to thecontroller 47 may be conducted by program command by generic programcontrolling said controller 47.

INDUSTRIAL APPLICABILITY

According to the present invention as described above, when a bipedwalking humanoid robot conducts various motions in series, a motioncontrol apparatus detects the robot's current posture and others, andonly when next motion command is within the range of stability limit,motion data is generated corresponding to next motion command.Consequently, a motion control apparatus drive-controls the robot'srespective portions based on said complementary and motion data, therebythe robot conducts the motion by next motion command from its currentposture. Thus, the robot can conduct motions in series smoothly andstably. Also only when next motion command is within the range ofstability limit, the robot conducts the motion corresponding to nextmotion command, and even if an operator to operate the robot isunaccustomed, the suitability and unsuitability of each continued motionare not required to be judged by the operator by combination of variousmotions by the robot operation, therefore easy operation of complexcontinuous motion is possible, and thereby conduction of unsuitablemotion by wrong operation by the operator can be prevented.

Further, if said motion control apparatus is provided with a motionlibrary storing the posture data of basic motions as the elements of therobot's motions, since various motions are realized by real timecombination of basic motions, in case that a robot is actually operatedunder the same circumstance as human beings, that is, the circumstancewhere the predicted conditions and reality do not necessarily agreebecause the circumstance varies irrelevantly with the robot operation,and also it varies due to the robot's own action, the robot can reactflexibly to the condition of the case. Further, the volume ofcalculation by the motion control apparatus is reduced, thereby quickgeneration of complementary and motion data is possible.

Thus, a quite excellent biped walking humanoid robot is provided inaccordance with the present invention, which can conduct various motionsin series easily and smoothly.

1. A biped walking humanoid robot comprising; a main body, a pair of legportions attached thereto at both sides of its lower part so as to beeach pivotally movable, each of the leg portions having a knee portionin its midway and a foot portion at its lower end, a pair of armportions attached to said main body at both sides of its upper part soas to be each pivotally movable, each of the arm portions having anelbow portion in its midway and a hand portion at its lower end, and ahead portion attached to the top end of said main body, drive meanspivotally moving pivotally movable joint portions of foot, lower thigh,and thigh portions of said leg portions, and hand, lower arm, and upperarm portions of said arm portions, and a motion control apparatusdrive-controlling respective drive means, characterized in that; saidmotion control apparatus compares, upon conducting various motions inseries, the robot's current posture and others including the robot'scurrent posture and dynamic state detected by a detector with nextmotion command input from outside, and judges if next motion command canbe conducted within the range of stability limit with respect to therobot's current posture and others, in case that the motion by nextmotion command can not be transferred stably, an intermediate motion isinserted, and each drive means is drive-controlled based on saidintermediate motion.
 2. A biped walking humanoid robot as set forth inclaim 1, characterized in that; said motion control apparatus isprovided with a motion library, the posture data of various fundamentalmotions as elements of a robot's motion is stored in said motionlibrary, said posture data includes auxiliary description indicatingpossible motions to the current posture, said motion control apparatusjudges if next motion command can be conducted within the range ofstability limit to the robot's current posture and others, referring tosaid auxiliary description of each posture data stored in said motionlibrary.
 3. A biped walking humanoid robot as set forth in claim 1 or 2,characterized in that; said motion control apparatus judges if saidintermediate motion can be stably transferred from a robot's currentposture to the motion by next motion command.
 4. A biped walkinghumanoid robot as set forth in claim 3, characterized in that; saidmotion control apparatus judges if said intermediate motion can bestably transferred from a robot's current posture to the motion by nextmotion command, referring to the auxiliary description of each posturedata stored in a motion library.
 5. A biped walking humanoid robot asset forth in claim 2, characterized in that; said motion controlapparatus reads out any of various posture data stored in said motionlibrary as said intermediate motion.
 6. A biped walking humanoid robotas set forth in claim 1, characterized in that; said motion controlapparatus, if next motion command is out of the range of stability limitwith respect to the robot's current posture and others, denotes tooutside said intermediate motion.
 7. A biped walking humanoid robotcomprising; a main body, a pair of leg portions attached thereto at bothsides of its lower part so as to be each pivotally movable, each of theleg portions having a knee portion in its midway and a foot portion atits lower end, a pair of arm portions attached to said main body at bothsides of its upper part so as to be each pivotally movable, each of thearm portions having an elbow portion in its midway and a hand portion atits lower end, and a head portion attached to the top end of said mainbody, joint drive motors pivotally moving pivotally movable jointportions of foot, lower thigh, and thigh portions of said leg portions,and hand, lower arm, and upper arm portions of said arm portions, and amotion control apparatus drive-controlling respective joint drivemotors, characterized in that; said motion control apparatus comprises;a motion planner judging if a next motion command input from outside ispracticable within the range of stability limit, and planning the motioncorresponding to the motion command based on the next motion commandinput from outside; a motion generator generating angle data ofrespective joint portions required for a robot's motion based on themotion plan by said motion planner; a compensator calculating ZMP (ZeroMoment Point) target value based on said angle data, and ZMP real valuebased on the posture information from an angle measurement unit and thedetected output from ZMP detection sensor, comparing said ZMP real valuewith said ZMP target value, and outputting ZMP compensation to saidmotion generator; a controller drive-controlling said respective motorsbased on the modified motion data from said motion generator; and amotion monitor monitoring the robot's state based on said motion plan,ZMP target value, and ZMP real value; and wherein said motion planner,upon conducting various motions in series, takes up a robot's currentposture and others from said motion monitor, as well as compares therobot's current posture and others with the next motion command inputfrom outside, and judges if said next motion command is practicablewithin the range of stability limit, and if the motion by next motioncommand can not be stably transferred, motion plan is conducted byinserting a intermediate motion.
 8. A biped walking humanoid robot asset forth in claim 7, characterized in that; the motion command inputinto said motion control apparatus is conducted with arbitrary motioncommand chosen by an operator by an outside control system.
 9. A bipedwalking humanoid robot as set forth in claim 7 or 8, characterized inthat; said motion control apparatus is provided with a motion library,the posture data of various fundamental motions as elements of a robot'smotion is stored in said motion library, said posture data includesauxiliary description indicating possible motions to the currentposture, said motion planner judges if next motion command can beconducted within the range of stability limit to the robot's currentposture and others, referring to said auxiliary description of eachposture data stored in said motion library.
 10. A biped walking humanoidrobot as set forth in claim 7 or 8, characterized in that; said motionplanner judges if said intermediate motion can be stably transferredfrom a robot's current posture to the motion by next motion command. 11.A biped walking humanoid robot as set forth in claim 10, characterizedin that; said motion planner judges if said intermediate motion can bestably transferred from a robot's current posture to the motion by nextmotion command, referring to the auxiliary description of each posturedata stored in said a motion library.
 12. A biped walking humanoid robotas set forth in claim 9, characterized in that; said motion plannerreads out any of various posture data stored in said motion library assaid intermediate motion.
 13. A biped walking humanoid robot as setforth in any one of claims 1, 2 and 5 to 8, characterized in that; saidmotion control apparatus is further provided with a history filter as amemory device to record motion command from outside.